| 摘要 |
PROBLEM TO BE SOLVED: To provide a highly versatile and inexpensive velocity detector allowing a velocity to be detected with high accuracy even in an extra-low velocity range. SOLUTION: This velocity detector includes: a latch signal preparer 21 for detecting an edge of an output pulse of an encoder; a rotative direction detector 32 for detecting a rotative direction based on the edge; a rotative direction holder 33; a time counter 23 for measuring time in synchronization with a velocity calculation period; data latches 25-1 to 25-4 for holding time measurement values from an output of the signal preparer 21; an edge change information holder 29 for detecting the state of a change in the edge within the calculation period to hold it as edge change information; and a CPU 30A for predicting a next appearing edge from the rotative direction and the change information in the event that no change arises in the edge within the calculation period to calculate a rotative velocity by using a time correction value proportional to the calculation period, a time measurement value, and the rotative direction. COPYRIGHT: (C)2010,JPO&INPIT |
